Information Technology & Systems

SUMMARY: Computer software is a set of programming instructions. Before starting coding, programmers must understand the user requirements and the flow of logic of the program.

Software developers can use the Program Development Lifecycle (PDLC) to define the program structure. The six phases of PDLC are defining the problem, designing the program, coding the program, testing and debugging the program, formalizing the solution, and maintaining the program.

Program designing begins with deciding the output and framing the program logic. The design is then broken down into modules to facilitate programming. All computer languages have a vocabulary of their own. If a programmer does not strictly follow the syntax of a programming language, the computer will not understand the commands given in the program.

First generation languages and second generation languages are regarded as low level languages, whereas the languages of higher generations are regarded as high-level languages. A machine language consists of binary numbers (0s and 1s) which respond directly to the on and off electrical pulses generated by the computer.

It is also called the first generation programming language. Assembly language is easier to use than machine language as a programmer can use symbols to sum up program instructions. High-level languages free programmers from the need to know the details of a processor, but they still require programmers to specify the procedure to be followed to solve a problem.

Fourth-generation languages free programmers from worrying about the procedures to be followed to solve a problem, but most of them are restricted to the use of accessing databases. An application generator facilitates the development of applications. It includes defining input transactions, editing such transactions, creating a database, updating files, generating reports, and processing queries.

The fifth generation programming languages are designed to enable the computer to solve a problem. These languages incorporate concepts like artificial intelligence, expert systems, etc. Language translators convert a source code into an object code. The two types of translators are compilers and interpreters. A compiler is a translation program which translates the entire source code of a high-level programming language into an object code and creates an object file. An interpreter is a program that executes the instructions which are written in a high-level language.